Adjustable transfer gripper cylinder

ABSTRACT

Adjustment mechanism for properly gripping paper sheets of different lengths to be transferred for multicolor printing including adjusting means for adjusting the circumferential spacing of cylinder gripping means, particularly on rotary printing machines. On one end of a shaft of a sheet transfer cylinder there is rotatably mounted a gear wheel and on one end of a shaft of a cylinder for turning papers sheets is a first drive gear and a second drive gear which is adjustable relatively to the first drive gear. One drive gear of the turning cylinder is engageable with the drive gear of the sheet transfer cylinder, so that changing of the rotational orientation between the drive gears of the sheet turning cylinder effects a rotation of the gear wheel of the sheet transfer cylinder and a change in the circumferential spacing between the mechanical grippers and the suction gripping elements thereof.

nite 3i ts et [19] jurny ADJUSTABLE TRANSFER GPPER CYLINDER [75] Inventor: .losef Jurny, Sebranice,

Czechoslovakia [73] Assignee: Adamovske Strojirny, narodni podnik, Adamov, Czechoslovakia [22] Filed: July 10, 1972 [21] App]. No.: 270,451

[30] Foreign Application Priority Data July 13. 1971 Czechoslovakia 5139-71 [52] US. (11..., 271/277, 1O1/230,271/82 [51] int. Cl B65h 5/12 [58] Field of Search 271/51,53, 80,82; 101/410, 230, 231, 246; 74/395 [56] References Cited UNITED STATES PATENTS 2,561,018' 7/1951 Gegenheimer .1 74/395 2,677,971 5/1954 Greenwood 74/395 2,757,610 8/1956 Gegenheimer et al 271/80 UX 3,430,946 3/1969 Siebke 271/51 Primary Examiner-Evon C. Blunk Assistant Examiner-Bruce l-l. Stoner, Jr. Attorney, Agent, or FirmMurray Schaffer [5 7 ABSTRACT Adjustment mechanism for properly gripping paper sheets of different lengths to be transferred for multicolor printing including adjusting means for adjusting the circumferential spacing of cylinder gripping means, particularly on rotary printing machines. On one end of a shaft of a sheet transfer cylinder there is rotatably mounted a gear wheel and on one end of a shaft of a cylinder for turning papers sheets is a first drive gear and a second drive gear which is adjustable relatively to the first drive gear. One drive gear of the turning cylinder is engageable with the drive gear of the sheet transfer cylinder, so that changing of the rotational orientation between the drive gears of the sheet turning cylinder effects a rotation of the gear wheel of the sheet transfer cylinder and a change in the circumferential spacing between the mechanical grippers and the suction gripping elements thereof.

7 Claims, 3 Drawing Figures 1 2 fuuiil Illll v llll-Illlllll llll Inn ,m'lillnlllli 2( Hulll ll [1- l lllll l-l I1I lillllllm nu nil-l Ii -pull n I l7 /5 [5 PATENTEU Aum 3mm mm mm QMQ ADJUSTABLE TRANSFER GRIPPER CYLINDER BACKGROUND OF INVENTION This invention relates to apparatus for adjustment of a paper sheet gripping mechanism, and more particularly to apparatus for properly gripping sheets of different lengths so that they are held fiat transfer cylinder by which such paper sheet may be turned over in rotary multicolor printing machines including adjusting means for adjusting the circumferential spacing of cylinder gripper means.

Multicolor printing machines are generally provided with a sheet turning mechanism so that printing can be effected on two sides of the paper. The trailing edge of the sheet which is being transferred from one printing unit to the following printing unit, is seized by grippers and delivered into the grippers of the impression cylinder of the next succeeding printing unit. To enable the precise grasping of the trailing edge of the paper sheet, the sheet must be properly grasped by suitable gripping means. This can be carried out by different seizing means, as for example, by means of suction elements which are arranged to grasp the trailing edge of the paper sheet. Since paper sheets of different sizes are frequently printed on multicolor printing machines, these mechanisms must therefore be provided with a device enabling the adjustment of the seizing means depending upon the size of the sheet to be printed.

ln hitherto known sheet transfer mechanisms for rotary multicolor printing machines the transfer cylinder is provided with a gripper mechanism adapted to seize the leading-edge of the paper sheet to be transferred. Suction elements are arranged on the surface of the transfer cylinder a predetermined distance from the gripper mechanism so that the suction cups are located under the trailing edge of the paper sheet. Suction elements, by means of a suction effect, hold the edge of the paper sheet to the surface of the sheet transfer cylinder. When the'edge of the paper sheet overlies the suction cups and is acted upon by the cups the suction elements move in a direction from the gripper mechanism opposite to the effect of inner spring means, and the paper sheet is thus held in a flat disposition on the surface of the transfer cylinder. A disadvantage of known devices of this kind is their complicated construction which leads to frequent failures.

It is an object of the present invention to provide apparatus for gripping paper sheets of different lengths in multicolor rotary printing presses which avoids the disadvantages of the prior art.

It is a further object to provide a simple and economical means for gripping paper sheets of different lengths being transferred from a transfer cylinder to a turning cylinder in multicolor rotary printing presses. These objects and others, together with numerous advantages will be found in the following disclosure.

SUMMARY OF INVENTION According to the present invention there is provided a device for the adjustment of a mechanism for gripping paper sheets to be transferred for multicolor printing, comprising at least one such sheet transfer cylinder having means for adjusting the circumferential spacing of cylinder gripper means and properly gripping sheets of different lengths carried by a sheet transfer cylinder and an associated sheet turning cylinder having gripping means for gripping the transferred sheet. A drive shaft for the sheet transfer cylinder carries a drive gear adjacent the outer end thereof and a gear wheel spaced therefrom. The sheet turning cylinder is provided with a drive shaft carrying a drive gear adapted to engage with the gear wheel of the sheet transfer cylinder and another drive gear spaced axially therefrom and adapted to be rotatably adjustable relative to one drive gear. The other drive gear of the turning cylinder is engageable with the drive gear of the sheet transfer cylinder, so that changing of the rotational orientation between the drive gears of the sheet turning cylinder effects a rotation of the gear wheel of the sheet transfer cylinder and a change in the circumferential spacing between the grippers and the retarding elements thereof.

It is preferred that the transfer cylinder carry end disc means rigidly connected to a drive gear. The discs mount grippers for the sheet transfer cylinder. Supporting segment means also are rotatably carried by the transfer cylinder and are rigidly connected to said drive gear and mounting suction elements for said sheet transfer cylinder. The suction elements and the grippers are spaced a predetermined circumferential distance about the periphery of the sheet transfer cylinder.

An advantage of the present invention is the provision of a simple and easy means for adjusting the mechanism-for gripping paper sheets under proper tension. A further advantage is the reduction of the possibility of recurring failures. Thus, there is a diminished loss of working time, and the productivity of the printing machine is thereby increased.

The invention may be more fully understood from the following disclosure, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWING In the drawings:

FIG. l is a side elevational view of the cylinders of a multicolor printing machine with the apparatus of this invention;

FIG. 2 is a plan view of the machine shown in FIG. 1 partially in section; and FIG. 3 is a sectional view of the apparatus associated with the sheet turning cylinder.

DESCRIPTION OF THE INVENTION Referring to FIGS. 1 and 2, there is shown a generally conventional arrangement of parallel impression, transfer and turning cylinders, between two printing units joined together for simultaneous rotation. Various structural details, such as the drive motor, transmission gearing, frame housing, etc., are omitted from the drawings since these. are well known and clearly obvious to those skilled in this art. Turning to the figures there is shown the impression cylinder 1 of the first printing unit, the shaft of which carries a drive gear 13 which is in engagement with a drive gear 14 rigidly mounted on the shaft of an adjacent transfer cylinder 2. The shaft of the transfer cylinder 2 also carries a second gear 15 arranged on the outer side of a side wall 21 of the frame of the printing machine. A sheet transfer cylinder 3 is mounted on a shaft 6 which is rotatably journalled in a gear wheel 20. On the outer side of the side wall 21 bypassing gear 20 the shaft is fixed to a drive gear 16 which engages the drive gear 15. A cylinder 4 adapted to turn the paper sheet is arranged parallel and adjacent to sheet transfer cylinder 3 and is provided with shaft 7 on which a first gear 17 is mounted meshing with gear 16. On the inner side of the side wall 21 shaft 7 mounts a second drive gear 18. The first drive gear 17 is adjustably mounted on shaft 7 so that it can be rotatably adjusted relative to the second drive gear 18. The impression cylinder of the next succeeding printing unit is mounted on a shaft which carries a drive gear 19 which engages with drive gear 18.

According to the present invention the sheet transfer cylinder 3 is constructed to permit the adjustment of the paper sheet gripping mechanism and comprises a pair of end discs 8 which are rigidly mounted on the shaft 6. The discs 8 straddle supporting segments 9 which are rotatably mounted on the shaft 6. The outermost arranged supporting segment 9 is connected to the gear wheel by means of an axial pivot pin 22. The end discs 8 mount a shaft 24 parallel to the central axis shaft 6 on which grippers 11 are arranged. The supporting segments 9 are connected by a tube 23 on which are mounted suction elements 10. The turning cylinder 4 is provided with a shaft parallel to its rotational axis 7 on which are arranged mechanical sheet grippers 12.

As seen in FIG. 3 the first drive gear 17 on shaft 7 is mounted coaxially about the hub of a third gear 28 which is securely fixed on the shaft 7. A pinion 27 is mounted within the circumference of the gear 17 and is adapted to engage the gear 28. A thrust disc 26 is fastened by means such as screws to the gear diametrically opposite the pinion 27 so that the pinion 27, gear 28 and gear 17 can be fixed together. A scale 31 is attached' on the hub of the gear 28 and a pointer is mounted on the first drive gear 17.

The device according to the invention operates as follows: the adjustment of the suction elements 10 according to the length of the paper sheets to be printed, in the direction to or from the grippers 11 of the transfer cylinder 3 is carried out by turning of the first drive gear 17 rotatably relative to second drive gear 18. This is accomplished by pinion 27 so that the first drive gear 17 is rotated relative to the second drive gear 18 whereby the disc 8 and segments 9, fixed to gears 16 and 20 respectively are rotated relative to each other to change the circumferential spacing between the grippers l1 and the suction cup 10. The suction cups 10 are thus shiftable with respect to the grippers 11 and the grippers 12 so that they may properly engage the opposite edge of the sheet held by the grippers 12, exerting a correct tension on it. The grippers 11 of the sheet transfer cylinder 3 are thus brought into such-a position relative to each of the printing units 1 and 5 that they are enabled to seize the trailing end 29 of a paper sheet carried by the grippers 12 of the cylinder 4 for turning paper sheets under the corrected tension. This occurs of course since the printing units 1 and 5 are driven through the gear chain composed of individual gears 13 through 19. The suction elements 10 themselves remain in a constant position relatively to the grippers 12 during operation, achieved by the fact that the supporting segments 9 are on the one hand interconnected by means of the tube 23 while on the other hand the outer supporting segments 9 are connected with the gear wheel 20 by means of pins 22. Thus the position of the suction cups once established remains fixed with regard to the turning drum 4.

Periodic adjustment can be effected by loosening the screws 25, releasing the thrust disc 26, as a result of which the pinion 27 can be turned. Being in engagement with the gear 28 it too is turned. By turning of the gear 28 the shaft 7 of cylinder 4 and drive gear 18 is turned relatively to the first drive gear 17. The degree of turning is indicated by the pointer 30 on the scale 31 and thus can be visually controlled as desired, depending upon the size of the paper sheets being printed.

Various modifications and embodiments will of course be evident to those skilled in this art. Accordingly, the foregoing disclosure is to be taken as illustrative only, and not limiting of the scope of the present invention.

What is claimed:

1. A device for adjusting the circumferential spacing of cylinder gripper means and for properly gripping sheets of different lengths carried by the sheet transfer cylinder of a multicolor printing machine including adjustable means for adjusting the circumferential spacing of the cylinder gripper means comprising a sheet transfer cylinder having first and second sections angularly adjustable with respect to each other, suction means mounted on said first section and mechanical gripping means for grasping the edge of said sheets mounted on said second section, said suction means being manually adjustable circumferentially relative to said mechanical gripping means for properly gripping sheets of different lengths, an associated sheet turning cylinder having means for gripping said sheet so transferred, a drive shaft for said sheet transfer cylinder rigidly connected to said second section and carrying a drive gear adjacent the outer end thereof and a rotatable gear wheel spaced therefrom and rigidly connected to said first section, said sheet turning cylinder having a drive shaft carrying a first drive gear and a second drive gear adapted to engage with the rotatable gear wheel of said sheet transfer cylinder, said first drive gear being spaced axially from said second gear and adapted to be rotatably adjustable relative to said second drive gear, said first drive gear being engageable with the drive gear of the sheet transfer cylinder, whereby changing of the rotational orientation between the first and second drive gears of said sheet turning cylinder effects a rotation of the rotatable gear wheel of said sheet transfer cylinder and a change in the circumferential spacing between the mechanical grippers and the suction gripping elements thereof.

2. The device according to claim 1 wherein the second section of the transfer cylinder also includes as a portion thereof end disc means rigidly connected to the drive gear, grippers mounted on said end disc means for said sheet transfer cylinder, the first section of the transfer cylinder including as a portion thereof supporting segment means, said supporting segment means being rigidly connected to said gear wheel and suction elements mounted on said segments of said sheet transfer cylinder, said suction elements and grippers being spaced a predetermined circumferential distance about the periphery of said sheet transfer cylinder.

3. The device according to claim 2, wherein a pair of said end discs are provided and the outer said discs is rigidly connected to said drive gear, a plurality of said supporting segments being provided and the outer of said segments being rigidly connected to said gear wheel, said discs carrying a shaft upon which the grippers of said sheet transfer cylinder are mounted, a tube connecting said supporting segments and mounting the suction elements of said sheet transfer cylinder.

4. The device according to claim 1, wherein said first drive gear of said sheet turning cylinder is detachably mounted upon a third gear carried by the drive shaft thereof, pinion means being provided in said first drive gear engageable with said third bear, whereby upon detachment of said first drive gear from said third gear rotation of said pinion means effects a rotation of said third gear and of said drive shaft and the second drive gear carried thereby.

5. The device according to claim 4, wherein said first mounted peripherally thereon.

* l= l l 

1. A device for adjusting the circumferential spacing of cylinder gripper means and for properly gripping sheets of different lengths carried by the sheet transfer cylinder of a multicolor printing machine including adjustable means for adjusting the circumferential spacing of the cylinder gripper means comprising a sheet transfer cylinder having first and second sections angularly adjustable with respect to each other, suction means mounted on said first section and mechanical gripping means for grasping the edge of said sheets mounted on said second section, said suction means being manually adjustable circumferentially relative to said mechanical gripping means for properly gripping sheets of different lengths, an associated sheet turning cylinder having means for gripping said sheet so transferred, a drive shaft for said sheet transfer cylinder rigidly connected to said second section and carrying a drive gear adjacent the outer end thereof and a rotatable gear wheel spaced therefrom and rigidly connected to said first section, said sheet turning cylinder having a drive shaft carrying a first drive gear and a second drive gear adapted to engage with the rotatable gear wheel of said sheet transfer cylinder, said first drive gear being spaced axially from said second gear and adapted to be rotatably adjustable relative to said second drive gear, said first drive gear being engageable with the drive gear of the sheet transfer cylinder, whereby changing of the rotational orientation between the first and second drive gears of said sheet turning cylinder effects a rotation of the rotatable gear wheel of said sheet transfer cylinder and a change in the circumferential spacing between the mechanical grippers and the suction gripping elements thereof.
 2. The device according to claim 1 wherein the second section of the transfer cylinder also includes as a portion thereof end disc means rigidly connected to the drive gear, grippers mounted on said end disc means for said sheet transfer cylinder, the first section of the transfer cylinder including as a portion thereof supporting segment means, said supporting segment means being rigidly connected to said gear wheel and suction elements mounted on said segments of said sheet transfer cylinder, said suction elements and grippers being spaced a predetermined circumferential distance about the periphery of said sheet transfer cylinder.
 3. The device according to claim 2, wherein a pair of said end discs are provided and the outer said discs is rigidly connected to said drive gear, a plurality of said supporting segments being provided and the outer of said segments being rigidly connected to said gear wheel, said discs carrying a shaft upon which the grippers of said sheet transfer cylinder are mounted, a tube connecting said supporting segments and mounting the suction elements of said sheet transfer cylinder.
 4. The device according to claim 1, wherein said first drive gear of said sheet turning cylinder is detachably mounted upon a third gear carried by the drive shaft thereof, pinion means being provided in said first drive gear engageable with said third bear, whereby upon detachment of said first drive gear from said third gear rotation of said pinion means effects a rotation of said third gear and of said drive shaft and the second drive gear carried thereby.
 5. The device according to claim 4, wherein said first drive gear and said third gear are adjustably connected by means of a thrust disc.
 6. The device according to claim 4, wherein a pointer and scale are mounted cooperatively upon said first drive gear and third gear and are adapted to provide an indication of the rotationaL orientation between the first and second drive gears of said sheet turning cylinder.
 7. The device according to claim 1, wherein the grippers of said sheet turning cylinder are carried by a shaft mounted peripherally thereon. 